JP7287057B2 - Video imaging device - Google Patents

Description

The present invention relates to a moving image capturing apparatus for capturing a moving image in an imaging field illuminated by a light source, and more specifically, a camera module for capturing moving images and an image capturing apparatus body for outputting captured moving images are connected by a single coaxial cable. The present invention relates to a moving image pickup device that is a digital camera.

A camera module that captures a moving image and an imaging device body that outputs the captured moving image transmit and receive imaging signals and control signals bidirectionally between the camera module and the imaging device body. In order to supply power to each part of the , it is necessary to connect using a power cable and many signal cables. A moving image capturing apparatus is known in which a camera module and an image capturing apparatus main body are connected together through a certain LVDS (Low Voltage Differential Signaling) cable (Patent Document 1).

5, a camera module 101 includes an imaging unit 102, an imaging control unit 103, a storage unit 104, a serial-parallel/parallel-serial conversion unit 105, and an LED 106 as a light source for blinking control. A serial-parallel/parallel-serial conversion unit 111 and an ISP (image signal processing unit) are installed in an imaging apparatus main body 110 connected to the driver 107 via an internal bus and connected to the camera module 101 via an LVDS cable 120 as a connection cable. signal processor) 112 and the video output unit 113 are connected by an internal bus.

The imaging unit 102 of the camera module 101 captures an image of the imaging field of view at a predetermined cycle, and sequentially outputs an imaging signal representing each frame image as a stream together with its imaging timing information to a serializer/parallel/serial conversion unit 105 as a serializer. . The imaging control unit 103 controls each imaging operation such as AF control, AE control, and AWB control of the imaging unit 102 based on an imaging control signal output from the ISP 112 of the imaging device main body 110. Based on the imaging timing information output from 102, a light source control signal for controlling blinking of the LED 106 is generated and output to the LED driver 107 to capture an image during the exposure period of the imaging element 102a of the imaging unit 102, that is, an image of the imaging field of view. The lighting of the LED 106 is controlled in synchronization with the period. The LED 106 is installed in the camera module 101 so as to illuminate the imaging field imaged by the imaging unit 102, so that the image of the imaging field illuminated by the LED 106 is captured.

The ISP 112 of the imaging device main body 11 generates a moving image by connecting imaging signals representing one frame image, and outputs the moving image from the moving image output unit 113 to an external monitor or the like. Also, the ISP 112 generates an imaging control signal for correcting the frame image from each input frame image, and outputs it to the imaging control unit 103 via the LVDS cable 120. The imaging control unit 103 generates the imaging control signal Since the image pickup operation of the image pickup unit 102 is controlled according to , the correction of the frame image is fed back to the frame image newly picked up by the image pickup unit 102 .

A DC power supply for driving each part of the camera module 101 excluding the LED 106 and the LED driver 107 is supplied from the imaging device main body 11 via an LVDS cable 120 connected to the camera module 101 . Since the LVDS cable 120 is also a bi-directional serial transmission line, the ACK signal responding to the imaging control signal in addition to the imaging signal and the imaging timing information is transmitted from the serial-parallel/parallel-serial converter 105 of the camera module 101 to the DC signal. The imaging control signal is superimposed on the power supply voltage and output to the imaging device main body 110, and the imaging control signal generated by the ISP 112 from the serial-parallel/parallel-serial conversion unit 111 of the imaging device main body 110 is applied to the DC power supply voltage of the LVDS cable 120. The images are superimposed and output to the imaging control unit 103 of the camera module 101 .

The DC power supply current for driving each part of the camera module 101 excluding the LED 106 and the LED driver 107 is about 300 mA, and the power consumption of each part is almost constant and stable, so the DC power supply voltage of the LVDS cable 120 fluctuates greatly. There is no change or disappearance of the above-mentioned signals other than the imaging signal superimposed on the DC power supply voltage, and no transmission/reception error occurs.

On the other hand, the power supply line of the LED 106 and the LED driver 107, whose drive current is as large as about 1 A and whose DC voltage fluctuates greatly when the LED 106 blinks, is connected to the LED power supply 114 of the imaging apparatus main body 110 using a dedicated power supply cable 121. I am letting

In this conventional video imaging device 100, the camera module and the imaging device main body are connected by only one coaxial cable, the DC power is supplied from the imaging device main body to the camera module via the coaxial cable, and the light source (LED) is supplied. Also known is a video imaging device that drives all circuit elements on the camera module side, including an LED driver (Patent Document 2).

JP 2017-147578 A JP 2015-154387 A

In the conventional video imaging device 100, the camera module 101 and the imaging device main body 110 are connected by two cables, the expensive LVDS cable 120 and the power cable 121. Therefore, the cost is high, the wiring is troublesome, and the appearance is aesthetically pleasing. also lose. In general, there are many cases where the installation location of a camera module that captures moving images and the body of an imaging device that is installed near a monitor that reproduces moving images are separated by several meters or more. .

As described in Patent Document 2, the above problem can be solved by connecting the camera module 101 and the imaging apparatus main body 110 with a single coaxial cable without wiring the power cable 121 separately. new problems arise. This problem will be described below with reference to FIG.

FIG. 6 is a timing chart showing the state of each part when the camera module 101 of the video imaging device 100 and the imaging device main body 110 are connected by one coaxial cable. As shown in the figure, the imaging device 102a captures an image of the imaging field of view during the exposure operation period from t0 to t1 at a cycle of 1/60 second in order to generate an imaging signal for one frame image. An image pickup signal representing one frame image picked up at the timing indicated by Vsync after the end time t1 is output. This image pickup signal is output to the ISP 112 of the image pickup device main body 110 via a coaxial cable to which a DC power supply voltage is applied to supply power from the image pickup device main body 110 to the camera module 101, so that it is pulse-modulated with the image pickup signal. The modulated signal is superimposed on the DC power supply voltage applied to the coaxial cable and output to the imaging device main body 110 side.

In order to illuminate the imaging field of view during imaging by the imaging unit 102, the lighting of the LED 106 is controlled in synchronization with the exposure operation period (t0-t1) of the imaging device 102a. The LED 106 is lit by being supplied with DC power from the imaging device main body 110 via a coaxial cable that connects the camera module 101 and the imaging device main body 110. Since the drive current for lighting the LED 106 is as large as about 1 A, The DC power supply voltage applied to the coaxial cable momentarily drops at t0 when the LED 106 is lit, and then gradually rises to the original applied voltage and stabilizes. Conversely, at time t1 when the LED 106 is turned off, the applied voltage rises instantaneously and then gradually decreases to the original applied voltage for a period of about 3 msec after t1, and stabilizes.

During the voltage fluctuation period in which the DC power supply voltage fluctuates after t1 when the LED 106 is turned off, the modulated signal pulse-modulated with the imaging signal as described above is added to the DC power supply voltage. A problem arises in that the rising or falling position changes due to fluctuations in the DC power supply voltage, and the imaging signal pulse-modulated on the imaging apparatus main body 110 side cannot be demodulated.

Similarly, output from the imaging control unit 103 to the ISP 112 in response to an imaging control signal (for example, SC1, SC2, SC3) output from the ISP 112 to the imaging control unit 103 at an arbitrary timing or an imaging control signal (SC1, SC2, SC3) Since the ACK signals (SA1, SA2, SA3) are also pulse-modulated and superimposed on the DC power supply voltage applied to the coaxial cable, as shown in FIG. SC2) and ACK signals (SA1, SA2) are output during the voltage fluctuation period immediately after blinking control times t0, t1 of the LED 106, demodulation is not possible and a communication error occurs.

For the above reasons, there has been a demand for a simple and inexpensive connection between the camera module of the moving image pickup device and the main body of the image pickup device using a single coaxial cable. I couldn't.

The present invention has been made in consideration of such conventional problems. It is an object of the present invention to provide a moving picture imaging device in which communication errors between device bodies do not occur.

In order to achieve the above-mentioned object, the moving picture imaging apparatus according to claim 1 captures an image of an imaging field of view during a predetermined exposure operation period, and generates an image signal representing each frame image captured after the exposure operation period ends. a camera module having an imaging unit that sequentially outputs together with the imaging operation timing information, a light source that illuminates the imaging field of view, and a light source control unit that controls blinking of the light source by a light source control signal generated based on the imaging operation timing information; , an image signal processing unit for generating and outputting a moving image in which each frame image is concatenated from the imaging signal sequentially output from the imaging unit and imaging operation timing information, and a DC power supply circuit for supplying DC power to the camera module. and a coaxial cable connecting the camera module and the imaging device main body. A video imaging apparatus in which an imaging signal sequentially output from an imaging unit and imaging operation timing information thereof are superimposed on a DC power supply voltage applied to a coaxial cable in a superimposing circuit and output to an image signal processing unit,
The first superimposing circuit coaxially combines the imaging signal sequentially output from the imaging unit and the imaging operation timing information thereof during a voltage stabilization period after a voltage fluctuation period set to a predetermined elapsed time from the time of flashing control of the light source. The imaging unit relatively delays the end of the exposure operation period from the light source extinguishing control, and the imaging signal and its imaging operation timing information are superimposed on the DC power supply voltage applied to the cable. It is characterized in that the voltage is output during the voltage stable period until the lighting control of the light source after a voltage fluctuation period set to a predetermined elapsed time has elapsed from the lighting control.

The DC power supply voltage applied to the coaxial cable fluctuates for a certain period from the time of flashing control of the light source. A voltage fluctuation period is set for a predetermined elapsed time from the time of flashing control. The first superimposition circuit of the camera module superimposes the imaging signal sequentially output from the imaging unit and the imaging operation timing information on the DC power supply voltage applied to the coaxial cable during the voltage stabilization period after the set voltage fluctuation period has elapsed. Therefore, it is possible to output to the main body of the imaging device without being affected by fluctuations in the DC power supply voltage. In addition, the imaging unit delays the end of the exposure operation period, or the light source control unit advances the turn-off control of the light source, or by both of these, the end of the exposure operation period is relatively delayed from the turn-off control of the light source. This can be delayed, and the output of the imaging signal and its imaging operation timing information during the voltage stabilization period after the voltage fluctuation period has passed can be advanced.

In the video imaging apparatus according to claim 2, the imaging unit sets the imaging signal and its imaging operation timing information to a predetermined elapsed time from the time of extinguishing control of the light source. The output timing after the end of the exposure operation period is delayed so that the output is performed during the voltage stabilization period until the end of the exposure operation period.

Since the light source control signal for controlling the blinking of the light source is generated based on the imaging operation timing information output from the imaging unit, the imaging unit outputs the imaging signal after the light source extinguishing control and the imaging operation timing information. After the voltage fluctuation period set to the predetermined elapsed time has elapsed from the light source extinguishing control, the voltage can be output with a delay during the voltage stabilization period until the next light source lighting control.

In the video imaging apparatus according to claim 3 , the camera module further has an imaging control section for controlling imaging operation of the imaging section according to the imaging control signal, and the image signal processing section performs imaging from the imaging signal representing each frame image. A control signal is generated, and a second superimposing circuit of the imaging device main body superimposes the imaging control signal generated by the image signal processing unit on the DC power supply voltage applied to the coaxial cable, and outputs it to the imaging control unit. It is characterized by

An imaging control signal generated from an imaging signal representing each frame image is output to the imaging control unit via a coaxial cable, and the imaging control unit controls imaging operation of the imaging unit according to the imaging control signal.

In the moving picture imaging apparatus according to claim 4 , the first superimposing circuit superimposes the timing information of the voltage stabilization period output from the imaging unit on the DC power supply voltage applied to the coaxial cable, and outputs the information to the image signal processing unit. The second superimposing circuit is characterized in that the imaging control signal is superimposed on the DC power supply voltage applied to the coaxial cable during the voltage stabilization period and output to the imaging control section.

Since the image signal processing unit receives timing information for the voltage stabilization period from the first superimposition circuit of the camera module, the imaging control signal generated by the image signal processing unit is applied to the coaxial cable from the second superimposition circuit during the voltage stabilization period. can be superimposed on the DC power supply voltage and output to the imaging control unit.

In the moving picture imaging apparatus according to claim 5 , the first superimposing circuit superimposes the timing information of the voltage stabilization period output from the imaging unit on the DC power supply voltage applied to the coaxial cable, and outputs the information to the image signal processing unit. The image signal processing unit is characterized by ignoring the ACK signal output by the imaging control unit in response to the imaging control signal when the ACK signal is input during a period other than the voltage stabilization period.

When an ACK signal is input during a period other than the voltage stabilization period, the imaging control signal in response to which the imaging control unit outputs the ACK signal, or the ACK signal is superimposed on the DC power supply voltage of the coaxial cable during the voltage fluctuation period. Since there is a possibility that a communication error has occurred, the image signal processing unit ignores the ACK signal and assumes that the imaging control signal has not been recognized by the imaging control unit.

In the video imaging apparatus according to claim 6 , when the imaging control unit receives the imaging control signal output from the image signal processing unit during the voltage fluctuation period, the imaging control signal is ignored and the ACK signal is not output. It is characterized by

When the imaging control unit inputs the imaging control signal during the voltage fluctuation period, the imaging control signal may change due to fluctuations in the superimposed DC power supply voltage. By not outputting the ACK signal, the image signal processing unit is notified that the imaging control signal has been ignored without controlling the operation.

According to the first aspect of the invention, a camera module having a light source for illuminating an imaging field of view can be connected to the imaging apparatus body with only one coaxial cable, and an imaging signal captured by the camera module can be accurately transmitted via the coaxial cable. can be sent to the main body of the imaging device at the same time.

According to the invention of claim 2, after the voltage fluctuation period set to the predetermined elapsed time has elapsed from the time of light-off control of the light source, the imaging signal and its imaging operation timing are generated during the voltage stabilization period until the next time of light-on control of the light source. Since the information can be superimposed on the DC power supply voltage of the coaxial cable, the imaging signal captured by the camera module can be transmitted to the imaging apparatus body via the coaxial cable without causing communication errors.

According to the third aspect of the present invention, the exposure operation period of the imaging unit ends during the voltage fluctuation period after the light source is extinguished. The imaging signal and its imaging operation timing information can be output during the voltage stabilization period.

According to the invention of claim 4, the image signal processing section generates an imaging control signal for correcting the frame image from each input frame image, and outputs it to the imaging control section via the coaxial cable. Image compensation can be fed back to a frame image newly captured by the imaging unit.

According to the invention of claim 5, the imaging control signal generated by the image signal processing section can be superimposed on the DC power supply voltage applied to the coaxial cable during the voltage stabilization period, and can be accurately transmitted to the imaging control section.

According to the sixth aspect of the invention, the imaging control signal output during a period other than the voltage stabilization period may change to a different signal due to a communication error. The imaging control signal can be resent or a new imaging control signal can be output.

According to the invention of claim 7, the operation of the imaging unit is not erroneously controlled according to the imaging control signal that may have changed due to a communication error, and the image signal processing detects that the imaging operation was not controlled according to the imaging control signal. You can tell the department.

1 is a block diagram showing a moving image capturing device 1 according to an embodiment of the present invention; FIG. 4 is a timing chart showing operation timings of respective units of the video imaging apparatus 1; FIG. 11 is a block diagram showing a video imaging device 30 according to a second embodiment; FIG. 4 is a timing chart showing operation timings of respective units of the video imaging device 30. FIG. 1 is a block diagram showing a conventional video imaging device 100; FIG. 4 is a timing chart showing operation timings of each part of the video imaging device 100 using coaxial cables.

A video imaging device 1 according to an embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. This moving picture imaging apparatus 1 generates a moving picture from a camera module 10 having an imaging unit 11 for capturing an image of an imaging field of view and a light source 14 for illuminating the imaging field of view, and imaging signals continuously input from the camera module 10. An imaging apparatus main body 20 having an image signal processing unit 21 for outputting an image is connected by one coaxial cable 2 . A DC power supply voltage of 5V is applied to the core wire of the coaxial cable 2 from the DC power supply circuit 22 of the imaging device main body 20 to supply DC power to each part of the camera module 10 including the light source 14, and the coaxial cable 2 Both forward communication in which an imaging signal, imaging operation timing information, etc., which will be described later, are transmitted from the camera module 10 to the imaging device main body 20, and reverse communication, in which an imaging control signal, which will be described later, is transmitted from the imaging device main body 20 to the camera module 10 via Two-way communication is performed.

The video imaging device 1 according to the present embodiment is used in a doze monitoring system that issues a drowsy driving warning from the facial expression of a driver driving a vehicle, and the camera module 10 is illuminated with infrared light even at night. An imaging unit 11 for an infrared camera capable of capturing with high sensitivity the facial expression of a driver who is driving, a serializer 12 that serves both as an imaging control unit and a modulation/demodulation unit, a superimposition/separation circuit 13 connected to the terminal of the coaxial cable 2, and nighttime It has an infrared LED 14 that serves as a light source for illuminating infrared rays that do not hinder the driver from driving, and an LED driver 15 that controls the blinking of the infrared LED 14 .

The imaging unit 11 includes a focus unit, a lens having an aperture unit, an electronic shutter, an image sensor 11a, a signal processing circuit, an A/D conversion circuit, and an RGB gain correction circuit. Each imaging operation such as AF control, AE control, and AWB control is controlled by an imaging control signal output from the image signal processing circuit 21 of the serializer 12 via the imaging control unit of the serializer 12 .

Among them, the image pickup device 11a of the image pickup unit 11 is composed of a CMOS sensor made up of a large number of pixels in a matrix in which pixel lines each made up of a group of pixels arranged in the row direction are arranged in a plurality of lines in the column direction. Each time, the signal charge accumulated by the photodiode is output as a pixel signal composed of a voltage signal. The imaging operation of the imaging device 11a is controlled by timing control signals of the exposure control signal and the readout control signal included in the imaging control signal output from the serializer 12, and is 1/30 second, which is the imaging cycle of one frame image, that is, about In one frame period TF of 33 msec, a frame image of the entire imaging field is captured, all pixel signals representing one frame image are read out, and output to the subsequent serializer 12 as analog imaging signals.

That is, as shown in FIG. 2, the image sensor 11a has an electronic function of a global shutter, receives a global reset exposure control signal, and the pixels of all pixel lines are exposed during the same exposure operation period (see FIG. 2). t0 to t1), and the output period synchronized with the vertical synchronization signal VSYNC during the voltage stabilization period Tvs described later after the second voltage fluctuation period Tvc2 described later has elapsed from t1 when the exposure operation period ended. During (the time from t2 to t3 in FIG. 2), the pixel signals representing the signal charges accumulated in the pixels of all the pixel lines are sequentially read out for each pixel line, and converted into an analog imaging signal representing a one-frame image. output to the serializer 12 of the

In addition, the imaging unit 11 adds imaging operation timing information of the exposure start time t0, the exposure end time t1, the output start time t2, and the output end time t3 when the one-frame image was captured to the above-described imaging signal, and and output to the LED driver 15 an LED control signal for controlling lighting of the infrared LED 14 during the exposure operation period (time from t0 to t1 in FIG. 2) based on the imaging operation timing information, The LED driver 15 controls the lighting of the infrared LED 14 during the exposure operation period according to this LED control signal, and illuminates the imaging field of view with infrared rays.

The modulation/demodulation unit of the serializer 12 pulse-frequency modulates the imaging signal input from the imaging unit 11, imaging operation timing information, and an ACK signal described later (hereinafter, these signals are referred to as forward communication signals), and the modulated amplitude is 200 mV. A modulated signal composed of a pulse signal is output to a superimposition/separation circuit 13 connected to the terminal of the coaxial cable 2 .

Also, the serializer 12 demodulates the imaging control signal output from the image signal processing unit of the imaging apparatus body 20 from the modulated signal input from the superimposition/separation circuit 13 in reverse communication, and demodulates the demodulated imaging control signal (for example, SC3) in FIG. 2) controls the operation of each part of the imaging unit 11, and when the imaging control signal is demodulated, generates an ACK signal (for example, SA3 in FIG. 2) and includes it in the forward communication signal.

However, the imaging control signal (for example, SC2 in FIG. 2) demodulated from the modulated signal by the serializer 12 is superimposed on voltage fluctuation periods Tvc1 and Tvc2, which will be described later and determined from imaging operation timing information input from the imaging unit 11. When input from the separation circuit 13, there is a possibility that part of the demodulated imaging control signal (SC2 in FIG. 2) contains an error. , a process of not outputting the ACK signal may be performed.

The superimposing/separating circuit 13, which is a first superimposing circuit, superimposes the modulated signal input from the serializer 12 on the DC power supply voltage of 5 V applied to the coaxial cable 2 and outputs (forward communication). is superimposed on the DC power supply voltage of 5 V, and the modulated signal output from the imaging apparatus body 20 is output to the serializer 12 .

Also, the 5V DC power supply is separated from the coaxial cable 2, and each part of the camera module 10 is supplied with the DC power supply for driving. Of these, the infrared LED 14 of the camera module 10 is lit by a DC power of 5 V and 1 A. Therefore, as shown in FIG. It drops momentarily, gradually rises during the illustrated first voltage fluctuation period Tvc1, and stabilizes at 5 V after the first voltage fluctuation period Tvc1 has passed.

Further, at time t1 when the infrared LED 14 is extinguished, the voltage of the core wire of the coaxial cable 2 momentarily rises from 5 V, gradually decreases during the illustrated second voltage fluctuation period Tvc2, and reaches After that, it returns to 5V and stabilizes. A first voltage fluctuation period Tvc1 until the voltage stabilizes after the lighting control t0 and a second voltage fluctuation period Tvc2 until the voltage stabilizes after the lighting control t1 correspond to the output power of the DC power supply circuit 22 and the infrared LED 14, respectively. Since it varies depending on the power consumption during lighting and other circuit constants, it should be set in advance based on actual measurement values. Therefore, as shown in FIG. 2, the period excluding the first voltage fluctuation period Tvc1 and the second voltage fluctuation period Tvc2 in one frame period TF becomes the voltage stabilization period Tvs in which the DC power supply voltage of the coaxial cable 2 is stabilized. Therefore, the superimposition/separation circuit 13 superimposes the imaging signal and the imaging operation timing information forward-communicated during the voltage stabilization period Tvs on the DC power supply voltage of the coaxial cable 2 .

A superimposing/separating circuit 23 , which is a second superimposing circuit connected to the other end of the coaxial cable 2 on the imaging device main body 20 side, applies the 5V DC power output from the DC power supply circuit 22 to the coaxial cable 2 . Also, the modulated signal input from the deserializer 24 is superimposed on the 5V DC power supply voltage applied to the coaxial cable 2 and output (reverse communication), and the camera module 100 outputs the 5V DC power supply voltage of the coaxial cable 2. A modulated signal composed of a pulse signal having an amplitude of 200 mV superimposed and output is separated and output to the deserializer 24 .

The deserializer 24 performs pulse frequency modulation with the imaging control signal input from the image signal processing unit 21, outputs a modulated signal composed of a pulse signal with an amplitude of 200 mV to the superimposition/separation circuit 23, and superimposes the signal by forward communication. • Demodulate the forward communication signal from the modulated signal input from the separation circuit 23 and output it to the image signal processing unit 21 .

The image signal processing unit 21 of the imaging device main body 11 generates a moving image by continuously capturing the imaging signal representing one frame image input from the deserializer 24, and generates a moving image signal based on the expression of the driver to warn of drowsy driving. Output to the outgoing doze monitoring system.

In addition, the image signal processing unit 21 generates an imaging control signal for correcting the frame image from each input frame image at an arbitrary timing, and superimposes the imaging control signal on the DC power supply voltage of the coaxial cable 2 by the reverse communication of the camera module 10 . is output to the serializer 12, which is an image pickup control unit. Since the serializer 12 controls the imaging operation of the imaging section 11 according to this imaging control signal, the correction of the frame image is fed back to the frame image newly captured by the imaging section 11 .

In the present embodiment, the lighting control time t0 and the extinguishing control time t1 of the infrared LED 14 are equal to the exposure start time t0 and the exposure end time t1, respectively, and the first voltage fluctuation period Tvc1 and the second voltage fluctuation period Tvc2 are set in advance. Therefore, the image signal processing unit 21 uses the exposure start time t0 and the exposure end time t1 included in the imaging operation timing information output from the camera module 10 as part of the voltage stabilization period. As timing information, a voltage stable period Tvs in one frame period TF is obtained from the known first voltage fluctuation period Tvc1 and second voltage fluctuation period Tvc.

Therefore, the image signal processing unit 21 sets the ASK signal output from the serializer 12 of the camera module 10 in response to the imaging control signal generated at arbitrary timing to the voltage stabilization period Tvs determined from the voltage stabilization period timing information. When input from the deserializer 24 during periods other than the ASK signal (SA1 in FIG. 2), the imaging control signal ( SC1 in FIG. 2), it is presumed to have been output in response to the imaging control signal (SC1 in FIG. 2) containing a communication error, the ACK signal is ignored, and the same imaging control signal is retransmitted.

According to this video imaging apparatus 1, even if the camera module 10 and the imaging apparatus main body 20 are connected only by one coaxial cable 2, the DC power supply voltage of the coaxial cable 2 is stabilized at 5 V during the voltage stabilization period Tvs. Since the modulated signal modulated by the imaging signal and the imaging operation timing information is superimposed on the DC power supply voltage of the coaxial cable 2, fluctuations in the DC power supply voltage may cause the pulse waveform of the modulated signal to be distorted, or the rising and falling positions to be shifted. The imaging signal and the imaging operation timing information can be accurately demodulated by the serializer 24 in the imaging apparatus body 20 and output to the image signal processing unit 21 without any change.

In addition, using the power cable 2 that supplies DC power to each part of the camera module 10, the image signal processing part 21 of the imaging device main body 20 outputs an imaging control signal for controlling the imaging operation of the imaging part 11 of the camera module 10. can. Furthermore, when the imaging control signal is output during the voltage fluctuation periods Tvc1 and Tvc2, the imaging control signal may be ignored on the camera module 10 side, or a communication error may occur in the image signal processing unit 21 of the imaging device body 20. It is possible to know that a valid imaging control signal has been output.

Next, a video imaging device 30 according to a second embodiment of the present invention will be described with reference to FIGS. 3 and 4. FIG. In the description of the second embodiment, the same reference numerals are assigned to components that act in the same or similar manner as the components of the first embodiment, and detailed description thereof will be omitted.

As shown in FIG. 4, this moving image capturing apparatus 30 is configured to detect the moving image capturing apparatus 1 according to the first embodiment at t4 before the end time t1 of the exposure operation period (time from t0 to t1 in FIG. 4). By extinguishing the infrared LED 14, the output start time t5 of the imaging signal after the end of the second voltage fluctuation period Tvc2 is advanced. As a result, all imaging signals representing one frame image and the imaging operation timing information are reliably superimposed on the DC power supply voltage of the coaxial cable 2 within the voltage stabilization period Tvs of one frame period TF, and sent to the imaging device main body 20 side. can be output.

An LED timing control unit 31 is connected between the imaging unit 11 of the camera module 10 and the LED driver 15 in order to turn off the infrared LED 14 at time t4 before the end time t1 of the exposure operation period. The LED timing control unit 31 detects the red light during the exposure operation period from t0 to t1 based on the imaging operation timing information including the exposure start time t0 and the exposure end time t1 when one frame image output from the imaging unit 11 is captured. An LED control signal is generated in which the extinguishing control time t4 of the outer LED 14 is earlier than the exposure end time t1, and is output to the LED driver 15. - 特許庁

In addition, the LED timing control unit 31 outputs the turn-off control time t4 included in the LED control signal to the serializer 12, and the serializer 12 applies the turn-off control time t4 to the imaging operation timing information input from the imaging unit 11 as a voltage. Include as timing information for the stable period.

Since the LED driver 15 controls the blinking of the infrared LED 14 by this LED control signal, the infrared LED 14 is extinguished at time t4, which is t1 before the exposure operation of the imaging device 11a ends. However, since the infrared LED 14 is lit during the period from t0 to t4 during the exposure period, the imaging device 11a can capture an image of the imaging field illuminated by the infrared LED 14. FIG.

According to this video imaging apparatus 30, the second voltage fluctuation period Tvc2 starts from the extinguishing control time t4 before the exposure operation period ends at t1, so the transition from the second voltage fluctuation period Tvc2 to the voltage stabilization period Tvs , the imaging device 11a of the imaging unit 11 can advance the output start time t5 of an analog imaging signal representing a one-frame image to be output to the serializer 12 after the end time t1 of the exposure operation period.

Further, in the present embodiment, the image signal processing unit 21 of the imaging device main body 20 controls the lighting control time (exposure start time) t0, which is the timing information of the voltage stabilization period included in the imaging operation timing information input from the deserializer 24. Then, the voltage stable period Tvs for each frame period _TF can be obtained from the extinguishing control time t4 and the known first voltage fluctuation period Tvc1 and second voltage fluctuation period Tvc2. The imaging control signals (SC4 and SC5 in FIG. 4) for correcting the frame image are output during the stabilization period Tvs, and the ACK signals (SA4 and SA5 in FIG. 4) in response from the serializer 12 are output during the voltage stabilization period Tvs. can. Therefore, even if the imaging control signal is superimposed on the DC power supply voltage of the coaxial cable 2, the imaging operation of the imaging unit 11 can be controlled without causing a communication error.

In this embodiment, the LED control signal generated by the LED timing control unit 31 is used to control the blinking of the infrared LED 14 so that the turn-off control time t4 of the infrared LED 14 is earlier than the exposure end time t1. 12, the operation of the imaging element 11a may be controlled so that the exposure end time t1 is delayed from the extinguishing control time t4 of the infrared LED 14, or both may be used together.

Also, the start time t5 of the output period for outputting the imaging signal is delayed from the end time t1 of the exposure operation period. The output of the imaging signal may be started at the end time t1 of the period.

Further, the image signal processing unit 21 outputs the imaging control signal at the timing when the imaging control signal is superimposed on the DC power supply voltage of the coaxial cable 2 during the voltage stabilization period Tvs. A buffer may be provided to superimpose the imaging control signal on the DC power supply voltage of the coaxial cable 2 during the voltage stabilization period Tvs.

On the other hand, in each of the above-described embodiments, the serializer 12 on the camera module 10 side outputs the forward communication signal at the timing of superimposing it on the DC power supply voltage of the coaxial cable 2 during the voltage stabilization period Tvs. The superposition/separation circuit 13 may superimpose the forward communication signal on the DC power supply voltage of the coaxial cable 2 during the voltage stabilization period Tvs.

Further, the moving picture imaging apparatuses 1 and 30 are not limited to those in which the camera module 10 and the imaging apparatus main body 20 are mounted on a vehicle, but can be applied to any moving picture imaging apparatus provided with a light source for illuminating the imaging field of view. can be applied.

It is suitable for a video imaging device that captures an image of an imaging field of view with a light source, and is suitable for a video imaging device in which an imaging device body and a camera module are connected by a power cable that supplies power to the light source of the camera module.

1, 30 video imaging device 2 coaxial cable 10 camera module 11 imaging unit 11a imaging element 12 serializer (modulation/demodulation unit, imaging control unit)
13 superimposition/separation circuit (first superimposition circuit)
14 infrared LED (light source)
15 LED driver (light source controller)
20 imaging device main body 21 image signal processing unit 22 DC power supply circuit 23 superimposing/separating circuit (second superimposing circuit)
24 Deserializer (modulator/demodulator)
31 LED timing control section Tvc1 First voltage fluctuation period Tvc2 Second voltage fluctuation period Tvs Voltage stabilization period

Claims (6)

An imaging unit that captures an image of an imaging field of view during a predetermined exposure operation period, and sequentially outputs an imaging signal representing each frame image captured after the end of the exposure operation period together with the imaging operation timing information, and a light source that illuminates the imaging field of view. and a light source control unit that controls blinking of the light source by a light source control signal generated based on the imaging operation timing information;
an image signal processing unit for generating and outputting a moving image in which each frame image is continuous from the imaging signal sequentially output from the imaging unit and imaging operation timing information; and a DC power supply circuit for supplying DC power to the camera module. and an imaging device main body having
A coaxial cable that connects the camera module and the imaging device main body,
A DC power supply voltage is applied from the DC power supply circuit to the coaxial cable to drive each section of the camera module, and a first superposition circuit of the camera module sequentially outputs imaging signals from the imaging section and imaging operation thereof. Timing information is superimposed on the DC power supply voltage applied to the coaxial cable and output to the image signal processing unit,
The first superimposing circuit combines the imaging signal sequentially output from the imaging unit and imaging operation timing information thereof during a voltage stabilization period after a voltage fluctuation period set to a predetermined elapsed time from the blinking control of the light source. is superimposed on the DC power supply voltage applied to the coaxial cable ,
The imaging unit relatively delays the end of the exposure operation period from the light source extinguishing control, and sets the imaging signal and its imaging operation timing information to a predetermined elapsed time from the light source extinguishing control. A moving image pickup apparatus , wherein output is performed during the voltage stabilization period until lighting control of the light source after the passage of the fluctuation period . The image pickup unit sets the image pickup signal and its image pickup operation timing information to the voltage stabilization period after a voltage fluctuation period for setting the image pickup signal and the image pickup operation timing information to a predetermined elapsed time from when the light source is controlled to be turned off, and to when the light source is controlled to be turned on. 2. The moving image pickup apparatus according to claim 1, wherein the output timing after the end of the exposure operation period is delayed so as to output the moving image to . The camera module further includes an imaging control section that controls an imaging operation of the imaging section according to an imaging control signal,
The image signal processing unit generates the imaging control signal from the imaging signal representing each frame image,
The second superimposing circuit of the imaging device main body superimposes the imaging control signal generated by the image signal processing unit on the DC power supply voltage applied to the coaxial cable, and outputs the superimposed signal to the imaging control unit. 3. The moving picture imaging apparatus according to claim 1 or 2 . The first superimposition circuit superimposes the timing information of the voltage stabilization period output from the imaging unit on the DC power supply voltage applied to the coaxial cable, and outputs the information to the image signal processing unit;
4. The imaging control unit according to claim 3 , wherein the second superimposing circuit superimposes the imaging control signal on the DC power supply voltage applied to the coaxial cable during the voltage stabilization period, and outputs the superimposed imaging control signal to the imaging control unit. Video imaging device. The first superimposition circuit superimposes the timing information of the voltage stabilization period output from the imaging unit on the DC power supply voltage applied to the coaxial cable, and outputs the information to the image signal processing unit;
The image signal processing unit is characterized by ignoring the ACK signal output by the imaging control unit in response to the imaging control signal when the ACK signal is input during a period other than the voltage stabilization period. 4. The moving image pickup apparatus according to claim 3 . The imaging control unit, when receiving the imaging control signal output from the image signal processing unit during the voltage fluctuation period, ignores the imaging control signal and does not output an ACK signal. Item 4. The moving image capturing apparatus according to item 3 .

Images